1. Field of the Invention
The present invention relates to a convertible shoe that can be converted from a walking shoe into an in-line skate by extending a swivel hinge wheel mechanism concealed in the sole of the shoe.
2. Description of the Related Art
Convertible shoes capable of converting from walking shoes into in-line skates are known in the art. One type of known convertible shoe comprises a shoe component, or upper, attached at its underside to a wheel mechanism, and to a sole. The wheel mechanism comprises wheels rotatably connected to an undercarriage, the undercarriage being connected to the underside of the upper. The wheel mechanism can be extended to allow a wearer to skate on a skating surface, or retracted to allow a wearer to walk. When extended, the wheel mechanism can provide clearance between the sole and the skating surface, and can support the upper some distance above the skating surface allowing the upper and sole to ride on the wheels or rollers. When retracted, the wheel mechanism provides no clearance between the upper and sole and the ground or skating surface and can be enclosed by the sole. The sole contains cavities that provide a storage enclosure for the retracted wheel mechanism.
There are inconveniences and problems associated with this type of known convertible shoe. Wheel diameter is limited to about 1 inch or less because the wheels must fit in the enclosing space provided by the sole. When the wheel mechanism is retracted, the wheels remain roughly perpendicular to the underside of the upper, so that their rolling axes are parallel to the upper's underside. Therefore, wheel diameter can generally be no greater than the thickness of the enclosing sole. The smaller the wheels' diameter, the greater the number of revolutions a wheel must make to travel a given distance, and the greater a wheel's wear. Small wheels are also generally less able to negotiate bumps and undulations in the skating surface. Further, small wheels can limit the clearance between the upper or sole and the skating surface, making skating more hazardous and preventing more aggressive skating. Examples of this type of convertible shoe are taught in U.S. Pat. No. 3,983,643 to Schreyer, U.S. Pat. No. 4,333,249 to Schaefer, U.S. Pat. No. 5,797,609 to Fichepain, and U.S. Pat. No. 5,785,327 to Gallant.
Another type of known convertible shoe is similar to the convertible shoe just described except that the sole is detachable. In this type of convertible shoe, the sole is generally attached to the upper when the wheel mechanism is retracted, thus covering and enclosing the retracted wheel mechanism, and allowing a wearer to walk in the convertible shoe. When the wheel mechanism is to be extended, the sole is removed and either must be set aside or carried separately by the wearer. In addition to the problems arising from small wheel diameters, having to remove and set aside, or carry, the sole is inconvenient for the wearer. An example of this type of convertible shoe is described in U.S. Pat. No. 3,979,842 to Texidor.
Still another type of known convertible shoe provides wheel mechanisms wherein the wheels are mounted at the sides of the sole and protrude therefrom. When used for skating, the wheels may be lowered, or extended downwards, to contact the skating surface and provide clearance between the sole of the shoe and the ground. When used for walking the wheels are raised by the sides of the shoe, allowing the sole to contact the ground. An example of this is described in U.S. Pat. No. 5,398,970 to Tucky. In an alternative design, the wheels are attachable to axles embedded in the sole. The wheels are attached to the axles when the shoe is to be used for skating and protrude from the sides of the sole. When used for walking, the wheels are removed. An example of this design is found in U.S. Pat. No. 5,511,824 to Kim. This type of convertible is not suitable for in-line skates because the wheels must be mounted on both sides of the sole. The Kim convertible shoe is also inconvenient because the wheels are not integral with the shoe, and they must be set aside or carried when the user is skating.
Known convertible shoe wheels that are integral with and fixed to the convertible shoe can be subject to uneven wheel wear. The wheels' orientation is generally fixed in a plane parallel to the direction of in-line skate travel, and the orientation cannot easily be reversed or rotated through 180 degrees. With prolonged skating, wheel wear can be uneven if, for example, the wearer's feet tilt inwards or outwards while skating. Unevenly worn wheels are undesirable because they are difficult to skate with.
Therefore, a need exists for improved integrated convertible shoes.